hw/s390x/s390-skeys.c

   1 /*
   2  * s390 storage key device
   3  *
   4  * Copyright 2015 IBM Corp.
   5  * Author(s): Jason J. Herne <jjherne@linux.vnet.ibm.com>
   6  *
   7  * This work is licensed under the terms of the GNU GPL, version 2 or (at
   8  * your option) any later version. See the COPYING file in the top-level
   9  * directory.
  10  */
  11
  12 #include "qemu/osdep.h"
  13 #include "qemu/units.h"
  14 #include "hw/boards.h"
  15 #include "hw/s390x/storage-keys.h"
  16 #include "qapi/error.h"
  17 #include "qapi/qapi-commands-misc-target.h"
  18 #include "qapi/qmp/qdict.h"
  19 #include "qemu/error-report.h"
  20 #include "sysemu/kvm.h"
  21 #include "migration/register.h"
  22
  23 #define S390_SKEYS_BUFFER_SIZE (128 * KiB)  /* Room for 128k storage keys */
  24 #define S390_SKEYS_SAVE_FLAG_EOS 0x01
  25 #define S390_SKEYS_SAVE_FLAG_SKEYS 0x02
  26 #define S390_SKEYS_SAVE_FLAG_ERROR 0x04
  27
  28 S390SKeysState *s390_get_skeys_device(void)
  29 {
  30     S390SKeysState *ss;
  31
  32     ss = S390_SKEYS(object_resolve_path_type("", TYPE_S390_SKEYS, NULL));
  33     assert(ss);
  34     return ss;
  35 }
  36
  37 void s390_skeys_init(void)
  38 {
  39     Object *obj;
  40
  41     if (kvm_enabled()) {
  42         obj = object_new(TYPE_KVM_S390_SKEYS);
  43     } else {
  44         obj = object_new(TYPE_QEMU_S390_SKEYS);
  45     }
  46     object_property_add_child(qdev_get_machine(), TYPE_S390_SKEYS,
  47                               obj, NULL);
  48     object_unref(obj);
  49
  50     qdev_init_nofail(DEVICE(obj));
  51 }
  52
  53 static void write_keys(FILE *f, uint8_t *keys, uint64_t startgfn,
  54                        uint64_t count, Error **errp)
  55 {
  56     uint64_t curpage = startgfn;
  57     uint64_t maxpage = curpage + count - 1;
  58
  59     for (; curpage <= maxpage; curpage++) {
  60         uint8_t acc = (*keys & 0xF0) >> 4;
  61         int fp =  (*keys & 0x08);
  62         int ref = (*keys & 0x04);
  63         int ch = (*keys & 0x02);
  64         int res = (*keys & 0x01);
  65
  66         fprintf(f, "page=%03" PRIx64 ": key(%d) => ACC=%X, FP=%d, REF=%d,"
  67                 " ch=%d, reserved=%d\n",
  68                 curpage, *keys, acc, fp, ref, ch, res);
  69         keys++;
  70     }
  71 }
  72
  73 void hmp_info_skeys(Monitor *mon, const QDict *qdict)
  74 {
  75     S390SKeysState *ss = s390_get_skeys_device();
  76     S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
  77     uint64_t addr = qdict_get_int(qdict, "addr");
  78     uint8_t key;
  79     int r;
  80
  81     /* Quick check to see if guest is using storage keys*/
  82     if (!skeyclass->skeys_enabled(ss)) {
  83         monitor_printf(mon, "Error: This guest is not using storage keys\n");
  84         return;
  85     }
  86
  87     r = skeyclass->get_skeys(ss, addr / TARGET_PAGE_SIZE, 1, &key);
  88     if (r < 0) {
  89         monitor_printf(mon, "Error: %s\n", strerror(-r));
  90         return;
  91     }
  92
  93     monitor_printf(mon, "  key: 0x%X\n", key);
  94 }
  95
  96 void hmp_dump_skeys(Monitor *mon, const QDict *qdict)
  97 {
  98     const char *filename = qdict_get_str(qdict, "filename");
  99     Error *err = NULL;
 100
 101     qmp_dump_skeys(filename, &err);
 102     if (err) {
 103         error_report_err(err);
 104     }
 105 }
 106
 107 void qmp_dump_skeys(const char *filename, Error **errp)
 108 {
 109     S390SKeysState *ss = s390_get_skeys_device();
 110     S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
 111     const uint64_t total_count = ram_size / TARGET_PAGE_SIZE;
 112     uint64_t handled_count = 0, cur_count;
 113     Error *lerr = NULL;
 114     vaddr cur_gfn = 0;
 115     uint8_t *buf;
 116     int ret;
 117     int fd;
 118     FILE *f;
 119
 120     /* Quick check to see if guest is using storage keys*/
 121     if (!skeyclass->skeys_enabled(ss)) {
 122         error_setg(errp, "This guest is not using storage keys - "
 123                          "nothing to dump");
 124         return;
 125     }
 126
 127     fd = qemu_open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0600);
 128     if (fd < 0) {
 129         error_setg_file_open(errp, errno, filename);
 130         return;
 131     }
 132     f = fdopen(fd, "wb");
 133     if (!f) {
 134         close(fd);
 135         error_setg_file_open(errp, errno, filename);
 136         return;
 137     }
 138
 139     buf = g_try_malloc(S390_SKEYS_BUFFER_SIZE);
 140     if (!buf) {
 141         error_setg(errp, "Could not allocate memory");
 142         goto out;
 143     }
 144
 145     /* we'll only dump initial memory for now */
 146     while (handled_count < total_count) {
 147         /* Calculate how many keys to ask for & handle overflow case */
 148         cur_count = MIN(total_count - handled_count, S390_SKEYS_BUFFER_SIZE);
 149
 150         ret = skeyclass->get_skeys(ss, cur_gfn, cur_count, buf);
 151         if (ret < 0) {
 152             error_setg(errp, "get_keys error %d", ret);
 153             goto out_free;
 154         }
 155
 156         /* write keys to stream */
 157         write_keys(f, buf, cur_gfn, cur_count, &lerr);
 158         if (lerr) {
 159             goto out_free;
 160         }
 161
 162         cur_gfn += cur_count;
 163         handled_count += cur_count;
 164     }
 165
 166 out_free:
 167     error_propagate(errp, lerr);
 168     g_free(buf);
 169 out:
 170     fclose(f);
 171 }
 172
 173 static void qemu_s390_skeys_init(Object *obj)
 174 {
 175     QEMUS390SKeysState *skeys = QEMU_S390_SKEYS(obj);
 176     MachineState *machine = MACHINE(qdev_get_machine());
 177
 178     skeys->key_count = machine->maxram_size / TARGET_PAGE_SIZE;
 179     skeys->keydata = g_malloc0(skeys->key_count);
 180 }
 181
 182 static int qemu_s390_skeys_enabled(S390SKeysState *ss)
 183 {
 184     return 1;
 185 }
 186
 187 /*
 188  * TODO: for memory hotplug support qemu_s390_skeys_set and qemu_s390_skeys_get
 189  * will have to make sure that the given gfn belongs to a memory region and not
 190  * a memory hole.
 191  */
 192 static int qemu_s390_skeys_set(S390SKeysState *ss, uint64_t start_gfn,
 193                               uint64_t count, uint8_t *keys)
 194 {
 195     QEMUS390SKeysState *skeydev = QEMU_S390_SKEYS(ss);
 196     int i;
 197
 198     /* Check for uint64 overflow and access beyond end of key data */
 199     if (start_gfn + count > skeydev->key_count || start_gfn + count < count) {
 200         error_report("Error: Setting storage keys for page beyond the end "
 201                      "of memory: gfn=%" PRIx64 " count=%" PRId64,
 202                      start_gfn, count);
 203         return -EINVAL;
 204     }
 205
 206     for (i = 0; i < count; i++) {
 207         skeydev->keydata[start_gfn + i] = keys[i];
 208     }
 209     return 0;
 210 }
 211
 212 static int qemu_s390_skeys_get(S390SKeysState *ss, uint64_t start_gfn,
 213                                uint64_t count, uint8_t *keys)
 214 {
 215     QEMUS390SKeysState *skeydev = QEMU_S390_SKEYS(ss);
 216     int i;
 217
 218     /* Check for uint64 overflow and access beyond end of key data */
 219     if (start_gfn + count > skeydev->key_count || start_gfn + count < count) {
 220         error_report("Error: Getting storage keys for page beyond the end "
 221                      "of memory: gfn=%" PRIx64 " count=%" PRId64,
 222                      start_gfn, count);
 223         return -EINVAL;
 224     }
 225
 226     for (i = 0; i < count; i++) {
 227         keys[i] = skeydev->keydata[start_gfn + i];
 228     }
 229     return 0;
 230 }
 231
 232 static void qemu_s390_skeys_class_init(ObjectClass *oc, void *data)
 233 {
 234     S390SKeysClass *skeyclass = S390_SKEYS_CLASS(oc);
 235     DeviceClass *dc = DEVICE_CLASS(oc);
 236
 237     skeyclass->skeys_enabled = qemu_s390_skeys_enabled;
 238     skeyclass->get_skeys = qemu_s390_skeys_get;
 239     skeyclass->set_skeys = qemu_s390_skeys_set;
 240
 241     /* Reason: Internal device (only one skeys device for the whole memory) */
 242     dc->user_creatable = false;
 243 }
 244
 245 static const TypeInfo qemu_s390_skeys_info = {
 246     .name          = TYPE_QEMU_S390_SKEYS,
 247     .parent        = TYPE_S390_SKEYS,
 248     .instance_init = qemu_s390_skeys_init,
 249     .instance_size = sizeof(QEMUS390SKeysState),
 250     .class_init    = qemu_s390_skeys_class_init,
 251     .class_size    = sizeof(S390SKeysClass),
 252 };
 253
 254 static void s390_storage_keys_save(QEMUFile *f, void *opaque)
 255 {
 256     S390SKeysState *ss = S390_SKEYS(opaque);
 257     S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
 258     uint64_t pages_left = ram_size / TARGET_PAGE_SIZE;
 259     uint64_t read_count, eos = S390_SKEYS_SAVE_FLAG_EOS;
 260     vaddr cur_gfn = 0;
 261     int error = 0;
 262     uint8_t *buf;
 263
 264     if (!skeyclass->skeys_enabled(ss)) {
 265         goto end_stream;
 266     }
 267
 268     buf = g_try_malloc(S390_SKEYS_BUFFER_SIZE);
 269     if (!buf) {
 270         error_report("storage key save could not allocate memory");
 271         goto end_stream;
 272     }
 273
 274     /* We only support initial memory. Standby memory is not handled yet. */
 275     qemu_put_be64(f, (cur_gfn * TARGET_PAGE_SIZE) | S390_SKEYS_SAVE_FLAG_SKEYS);
 276     qemu_put_be64(f, pages_left);
 277
 278     while (pages_left) {
 279         read_count = MIN(pages_left, S390_SKEYS_BUFFER_SIZE);
 280
 281         if (!error) {
 282             error = skeyclass->get_skeys(ss, cur_gfn, read_count, buf);
 283             if (error) {
 284                 /*
 285                  * If error: we want to fill the stream with valid data instead
 286                  * of stopping early so we pad the stream with 0x00 values and
 287                  * use S390_SKEYS_SAVE_FLAG_ERROR to indicate failure to the
 288                  * reading side.
 289                  */
 290                 error_report("S390_GET_KEYS error %d", error);
 291                 memset(buf, 0, S390_SKEYS_BUFFER_SIZE);
 292                 eos = S390_SKEYS_SAVE_FLAG_ERROR;
 293             }
 294         }
 295
 296         qemu_put_buffer(f, buf, read_count);
 297         cur_gfn += read_count;
 298         pages_left -= read_count;
 299     }
 300
 301     g_free(buf);
 302 end_stream:
 303     qemu_put_be64(f, eos);
 304 }
 305
 306 static int s390_storage_keys_load(QEMUFile *f, void *opaque, int version_id)
 307 {
 308     S390SKeysState *ss = S390_SKEYS(opaque);
 309     S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
 310     int ret = 0;
 311
 312     while (!ret) {
 313         ram_addr_t addr;
 314         int flags;
 315
 316         addr = qemu_get_be64(f);
 317         flags = addr & ~TARGET_PAGE_MASK;
 318         addr &= TARGET_PAGE_MASK;
 319
 320         switch (flags) {
 321         case S390_SKEYS_SAVE_FLAG_SKEYS: {
 322             const uint64_t total_count = qemu_get_be64(f);
 323             uint64_t handled_count = 0, cur_count;
 324             uint64_t cur_gfn = addr / TARGET_PAGE_SIZE;
 325             uint8_t *buf = g_try_malloc(S390_SKEYS_BUFFER_SIZE);
 326
 327             if (!buf) {
 328                 error_report("storage key load could not allocate memory");
 329                 ret = -ENOMEM;
 330                 break;
 331             }
 332
 333             while (handled_count < total_count) {
 334                 cur_count = MIN(total_count - handled_count,
 335                                 S390_SKEYS_BUFFER_SIZE);
 336                 qemu_get_buffer(f, buf, cur_count);
 337
 338                 ret = skeyclass->set_skeys(ss, cur_gfn, cur_count, buf);
 339                 if (ret < 0) {
 340                     error_report("S390_SET_KEYS error %d", ret);
 341                     break;
 342                 }
 343                 handled_count += cur_count;
 344                 cur_gfn += cur_count;
 345             }
 346             g_free(buf);
 347             break;
 348         }
 349         case S390_SKEYS_SAVE_FLAG_ERROR: {
 350             error_report("Storage key data is incomplete");
 351             ret = -EINVAL;
 352             break;
 353         }
 354         case S390_SKEYS_SAVE_FLAG_EOS:
 355             /* normal exit */
 356             return 0;
 357         default:
 358             error_report("Unexpected storage key flag data: %#x", flags);
 359             ret = -EINVAL;
 360         }
 361     }
 362
 363     return ret;
 364 }
 365
 366 static inline bool s390_skeys_get_migration_enabled(Object *obj, Error **errp)
 367 {
 368     S390SKeysState *ss = S390_SKEYS(obj);
 369
 370     return ss->migration_enabled;
 371 }
 372
 373 static SaveVMHandlers savevm_s390_storage_keys = {
 374     .save_state = s390_storage_keys_save,
 375     .load_state = s390_storage_keys_load,
 376 };
 377
 378 static inline void s390_skeys_set_migration_enabled(Object *obj, bool value,
 379                                             Error **errp)
 380 {
 381     S390SKeysState *ss = S390_SKEYS(obj);
 382
 383     /* Prevent double registration of savevm handler */
 384     if (ss->migration_enabled == value) {
 385         return;
 386     }
 387
 388     ss->migration_enabled = value;
 389
 390     if (ss->migration_enabled) {
 391         register_savevm_live(NULL, TYPE_S390_SKEYS, 0, 1,
 392                              &savevm_s390_storage_keys, ss);
 393     } else {
 394         unregister_savevm(DEVICE(ss), TYPE_S390_SKEYS, ss);
 395     }
 396 }
 397
 398 static void s390_skeys_instance_init(Object *obj)
 399 {
 400     object_property_add_bool(obj, "migration-enabled",
 401                              s390_skeys_get_migration_enabled,
 402                              s390_skeys_set_migration_enabled, NULL);
 403     object_property_set_bool(obj, true, "migration-enabled", NULL);
 404 }
 405
 406 static void s390_skeys_class_init(ObjectClass *oc, void *data)
 407 {
 408     DeviceClass *dc = DEVICE_CLASS(oc);
 409
 410     dc->hotpluggable = false;
 411     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
 412 }
 413
 414 static const TypeInfo s390_skeys_info = {
 415     .name          = TYPE_S390_SKEYS,
 416     .parent        = TYPE_DEVICE,
 417     .instance_init = s390_skeys_instance_init,
 418     .instance_size = sizeof(S390SKeysState),
 419     .class_init    = s390_skeys_class_init,
 420     .class_size    = sizeof(S390SKeysClass),
 421     .abstract = true,
 422 };
 423
 424 static void qemu_s390_skeys_register_types(void)
 425 {
 426     type_register_static(&s390_skeys_info);
 427     type_register_static(&qemu_s390_skeys_info);
 428 }
 429
 430 type_init(qemu_s390_skeys_register_types)